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Visar resultat 1 - 5 av 11 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Efficiency factors for space heating system in buildings

   Författare :Christian Brembilla; Thomas Olofsson; Ronny Östin; Mohsen Soleimani-Mohseni; Bjørn Reidar Sørensen; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Efficiency factors of space heating; hydronic panel radiator; hydronic floor heating; multilayer wall; numerical modelling; room control volume; decrement factor; time delay; heat conduction; heat convection; heat radiation; heat storage; thermal inertia; Euler solver; Newton-Raphson method; synthetic weather file; feedback and feed-forward control strategies; adaptive control; validation methodology; uncertainty bands; robustness of model predictions; thermostatic booth simulator; differential sensitivity analysis; transient model of panel radiator with multiple storage elements; active thermal mass; benchmark performance indicator; linear regression model; calibration through uncertainty bands; hybrid model of low-energy building: law driven data driven; outdoor temperature compensation heating curve; solar radiation model; finite difference method; heat equation;

   Sammanfattning : The thesis focuses on the efficiency of the space heating system. In particular, the efficiency factors measure the efficiency of thermal zone. The efficiency factors measures how the energy is used in a space heating. LÄS MER

3. 2. Data Assimilation in Fluid Dynamics using Adjoint Optimization

   Författare :Johan Lundvall; Vladimir Kozlov; Per Weinerfelt; Matts Karlsson; Anders Szepessy; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Data assimilation; Inverse problem; Adjoint optimization; Burgers equation; nonlinear; Landweber; Initial pressure; Euler flow; Applied mathematics; Tillämpad matematik;

   Sammanfattning : Data assimilation arises in a vast array of different topics: traditionally in meteorological and oceanographic modelling, wind tunnel or water tunnel experiments and recently from biomedical engineering. Data assimilation is a process for combine measured or observed data with a mathematical model, to obtain estimates of the expected data. LÄS MER

4. 3. A Linearized Euler Method for Unsteady Flow in Axial-Flow Turbomachines

   Författare :J. Pieter Groth; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : A linear Euler method for analysing unsteady inviscid compressible quasi three- dimensional flows in oscillating cascades is developed. It is applicable to both blade flutter and forced response problems. LÄS MER

5. 4. A study of hydroelastic fluid-structure interaction with application to immersed cantilevers

   Författare :Johan Lorentzon; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Partitioned Fluid-Structure; Blocked Gauss-Seidel; Jacobian-free Newton-Krylov methods; Incompressible fluid; Finite Strain; Total Lagrangian; Arbitrary Lagrange Euler method; Vector acceleration;

   Sammanfattning : This study presents an approach for partitioned fluid-structure interaction (FSI) applied to large structural deformations, where an incompressible turbulent solver is combined with a structural solver. The implementation is based upon two different open-source libraries by using MPI as a parallel communication protocol, the packages deal. LÄS MER

7. 5. Thermo-Acoustic Properties in Combustion Chambers

   Författare :Guillaume Jourdain; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mode Stability Analysis; Computational Aeroacoustics; Screech mode; Arnoldi s Method; Buzz mode; Afterburner; Gas turbine combustor; Combustion instabilities;

   Sammanfattning : Design and analysis methods for gas turbine combustors or afterburners have to be improved in particular regarding the prediction of combustion instabilites. A methodology, which combines the use of a linearized flow solver and an Arnoldi algorithm performing the eigenmode extraction procedure, resolves eigenmodes which are candidates to these instabilities. LÄS MER